This requires a fully leveled up Royal Guard style. You must posses the ability called "Dreadnaught". Dreadnaught is performed by holding RB + Left Analog-stick Away + B. This ability encases you in invulnerable armor, based upon how full your royal gauge is. You can still perform Dreadnaught with an empty royal gauge and get about five seconds of invulnerability. You will also suffer limited movement during a Dreadnaught. Perform the Dreadnaught and at the precise moment it runs out, switch your melee weapon (RT). If done fast enough you will keep the Dreadnaught armor and be able to move freely. Note: You are still fully able to take damage, as well as move normally.